For decades, business phone lines ran over copper and ISDN: a box on the wall, a PBX in the server room, and channels you paid for one by one. That network is being retired all over Europe. Operators don't want to maintain two networks, and everything now runs over IP anyway. If your company still has an ISDN line, or a PBX that depends on one, the ISDN switch-off is a good moment to move to VoIP on your own schedule rather than your operator's.
What the ISDN switch-off means
"Switch-off" covers two things that often happen together:
- ISDN and analogue telephone services are replaced by voice over IP. Your operator moves you to an IP line, or ends the service.
- The copper network itself is shut down exchange by exchange as fibre takes over.
Either way, equipment that only speaks ISDN or analogue stops working unless something translates for it. That includes your PBX.
Where Europe stands
Timelines differ by country and by operator. Here's what the official sources say:
| Country | Status |
|---|---|
| Germany | Deutsche Telekom reported in early 2020 that its move to IP was nearly complete, with business customers to finish in 2020. Other carriers run their own schedules. |
| France | Orange is closing its copper network. According to Arcep, new copper lines can no longer be ordered in most towns since January 2026 (everywhere by January 2027), and lines are switched off in yearly batches until the end of 2030. |
| Italy | AGCOM approves the shutdown of old copper exchanges in batches: 2,055 exchanges in a 2025 decision alone, each with a notice period before it closes. |
| Spain | The CNMC said in 2023 that Telefónica's closure of its copper exchanges would be practically finished in 2025. |
| United Kingdom | Openreach says all ISDN-based services must move to IP by January 2027, or they will be ceased. |
Your own date depends on your exchange and your operator. If you've had a letter, it's on there. If not, ask your operator, and don't wait for the letter to start planning.
What still runs on your old line?
The phones are the obvious part. Before you switch, walk the building and list everything plugged into the old line or the old PBX:
- Fax machines
- Alarm systems and their connection to the monitoring centre
- Lift emergency phones
- Door intercoms and gate openers
- Card payment terminals and franking machines on dial-up
- Modems for remote maintenance of machines or heating
Each needs a plan. Some move to an IP connection or a mobile transmitter, which is a job for the maintenance company. Analogue devices that must stay can connect to a VoIP gateway. Yeastar makes FXS gateways that plug analogue devices into a P-Series PBX. Faxes can move to a virtual fax service: Yeastar P-Series connects to online fax providers, so you send and receive faxes from Linkus.
Your options for moving to VoIP
1. Keep the old PBX, add a gateway. A gateway connects your ISDN PBX to a SIP trunk. It's the smallest change, but you keep ageing hardware, its maintenance contract and its limits. It's a stopgap.
2. Replace it with a cloud PBX and a SIP trunk. Your numbers move to a SIP trunk, and a cloud PBX takes over the call handling: extensions, ring groups, queues, IVR, voicemail, recording. Your team calls from IP desk phones, from the desktop or from their mobiles with the Linkus apps. Nothing sits in the server room, and adding a person is a setting, not new hardware.
For most small and mid-sized companies, the second option costs less over a few years and removes the next deadline altogether.
A calm migration plan
- Take stock. Numbers, direct dial-in ranges, the devices listed above, your current call flows (who answers what, when).
- Choose a SIP trunk provider that serves your country and can port your numbers. Our country guides cover Germany, France, Italy and Spain.
- Set up the new PBX in parallel. Extensions, call routing, greetings. Test with a temporary number while the old system keeps running.
- Port your numbers on a quiet day. You start the port with the new provider, and our porting guide covers the steps.
- Switch off the old system once inbound and outbound calls work, and cancel the services you no longer need.
On PBXfactory
A Yeastar P-Series Cloud PBX from PBXfactory is ordered online and set up automatically, usually in under a minute. Your company's first PBX starts with a 3-day free trial for up to 10 seats, so you can test before the switch. After that it's €4.99 per seat per month or €54.99 per seat per year, prices excluding VAT. We don't sell SIP trunks or port numbers ourselves: you choose the provider, and porting runs through them. If you're moving from 3CX rather than ISDN, Crane carries your setup over for you.